New ground was broken literally and figuratively earlier this summer when recycled tires — or tire-derived aggregates (TDA) — were used for the first time in Ontario by the Ministry of Transportation at the site of the new $26-million Boundary Road Bridge over Highway 401 near Cornwall.
The north and south embankments were partially built with a tapered, three-metre-thick layer of TDA, which is shredded scrap tires generally ranging in length between 12 millimetres (0.5 inches) and 305 millimetres (12 inches). About 3,000 tonnes were used.
Installed at the maximum three-metre-thickness to limit internal heating, the shredded bits were spread out with a D5 dozer, compacted by a vibratory steel drum roller, wrapped with a protective geotextile fabric, and then covered with two metres of soil to limit air and water infiltration. There are also several granular drains to remove any water that does get in. Below the layer are two metres of borrow material.
- Reprinted with permission from the Daily Commerical News and Construction Record. For more check out http://dcnonl.com/article/id51678/--cornwall-ontario-bridge-project-uses-recycled-tires.